Method of making wrapped tubular concrete

ABSTRACT

Method of making reinforced concrete inclusive of hollow concrete body of tubular shape having beveled end and reinforcing member wrapped on exterior surface of length of concrete body at beveled end in progression of wraps to form continuous helical assembly. Reinforcing assembly under lesser tension extends along shorter side portion than longer side portion to provide more nearly equal stress in concrete body. Means associated with concrete body onto which reinforcing member is wrapped is utilized for holding reinforcing member against circumferential movement to maintain said preselected tension in reinforcing member.

United StiltES Patent U91 Breitfuss et al.

[54] METHOD OF MAKING WRAPPED TUBULAR CONCRETE [751 Inventors: Thomas K. Breitfuss, Tustin; Floyd L. Wallace, La Habra; Joseph P. Zicaro, Tustin, all of Calif.

[73] Assignee: Hydro Conduit Orange, Calif.

Corporation,

[521 U.s.c| ..242/7.o2,242 7.22 51 riii.ci....- .nssii'saloo, B65h 81/08 [58] Field of Search ..242/7.22, 7.21, 7.23, 7.13, 242/147 R, 702; 138/176 [56 v A References Cited [451 Ar.3,i973

3,052,419 9/1962 Huck .,.242/7.22

FOREIGN PATENTS OR APPLICATIONS 963,260 4/1957 Germany", ..'....242/7.l3

Primary Examiner-BillyS. Taylor Attorney-McGrew and Edwards [57] ABSTRACT Method of making reinforced concrete inclusive of hollow concrete body of tubular shape having beveled end and reinforcing member wrapped on exterior surface of length of concrete body at beveled end in progression of wraps to form continuous helical assembly. Reinforcing assembly under lesser tension extends along shorter side portion than longer side portion to provide more nearly equal stress in concrete body. Means associated with concrete body onto which reinforcing member is wrapped is utilized for holding reinforcing member against circumferential movement to maintain said preselected tension in UNITED STATES PATENTS remfm'cmg member- 3,227,383 1/1966 Z ywietz ..242/7.13 4Claims,7l)rawing Figures 2a a v '%i 2e 24 25 g g? PATENTEBAPRS I975 3.724.768

sum 1 [1F 2 INVENTORS THOMAS K. BREITFUSS FLOYD L WALLACE BY JOSEPH. P. ZICARO 0%1 mljq A T TOR/V5 Y5 PATENTEDAPM I975 3,724,768

SHEET 2 [1F 2 FIG.6

THOMAS K. BREITFUSS FLOYD L. WALLAgE BY JOSEPH P. ZICAR F IG. 7

A TTORNEYS METHOD OF MAKING WRAPPED TUBULAR CONCRETE The present application is a division of Ser. No. 696,402, filed Jan. 8, 1968, and now [1.5. Pat. No. 3,587,659.

This invention relates to prestressed concrete and more particularly to improvements in hollow concrete bodies reinforced by a tension member being wrapped lengthwise of the body.

Hollow concrete bodies or tubular sections such as concrete pipe, piling or tanks are frequently reinforced by tension members such as reinforcing rods, wires or strand material being wrapped on the exterior surface of the pipe under tension to achieve compression or stress in the concrete body which will oppose later stresses produced under loading. For many applications, one or both ends of the pipe are not perpendicular to the side walls producing sides or halves of unequal width such as what is commonly referred to as a beveled pipe section.

l-leretofore in order for these beveled sections to withstand design loads, it has been the practice to place a thick metal section at the bevel or to wrap reinforcing or prestressing material under a constant tension throughout its length and in a manner so that the long side or portion has the same number of wraps as the short side or portion. With such an arrangement there is lesser spacing between applied wraps on the shorter side of the beveled end portion than on the longer side and such a difference in spacing provides greater stress on the shorter side as compared with the long side.

Accordingly it is an object of this invention to pro- 1 vide a method of producing reinforced hollow concrete with a preselected unequal tension in the reinforcing member wrapped on a selected portion of the hollow concrete.

Another object of this invention is to provide a method of producing a hollow concrete body of the type having side dimensions of unequal length wrapped with a continuous reinforcing assembly so as to exert more nearly equal stresses in said concrete body.

Still a further object of this invention is to provide a method of producing reinforced hollow concrete having means for holding a continuous wrap of reinforcing member on a surface of concrete body against circumferentialmovement to maintain established differential tension on the reinforcing member.

It is still another object of this invention to provide a method of making a hollow concrete body having side dimensions of unequal length and reinforced by a tension member wrapping about its periphery to produce more nearly balanced stresses in the body.

Other objects, advantages, and capabilities of the present invention will become apparent as the following description proceeds taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevation view of a tubular concrete body section of the beveled type;

FIG. 2 is a side elevationview of a tubular concrete body section as shown in FIG. 1 with the reinforcing or prestr'ess ing member wrapped on its exterior with the final wrap being parallel to the beveled end;

FIG. 3 is a schematic diagram showing the approximate tension in the reinforcing member of each wrap for the assembly of FIG. 2 at the beveled end;

FIG. 4 is a side elevation view of a tubular concrete body section shown in FIG. 1 with the reinforcing member wrapped on its exterior surface and passing through or over holding members on the body disposed in a vertical plane which divides the body into a short side and a long side.

FIG. 5 is a schematic diagram showing the relative tension in the reinforcing member of each wrap for the assembly of FIG. 4 at the beveled end;

FIG. 6 is a structural schematic diagram with various components shown in a top plan view of one form of system for carrying out the controlled tensioning of the reinforcing member on the concrete body during wrapping; and FIG. 7 is a schematic diagram of the system shown in FIG. 6 with various structural components shown in a side elevation view.

Referring now to the drawings, a hollow concrete body 2 of tubular shape is shown in FIGS. 1 through 5 and while it is understood that such hollow bodies may take various forms and configurations, the present invention is particularly applicable to a typical beveled pipe section as illustrated in FIG. 1. This tubular body or pipe section 2 is beveled in that the surface 3 at one end is in a plane other than perpendicular to the axis of the pipe section. The axis or center line of the pipe section is designated XX.

The typical beveled pipe section 2 terminates in an end oppositely of the beveled end which is at right angles to the sides so that the entire tubular body or beveled pipe section will have what herein be referred to as a short side 7 and a long side 8. For a tubular body of circular section as shown the maximum circumferential extent of sides 7 and 8 is semicircular halves and the shortest lengthwise dimension for the body is at the midpoint of the semicircle of short side 7 and the longest lengthwise dimension for the body is at the midpoint of the semicircle of the long side 8.

Pipe section 2 as shown in FIG. 2 is provided with an elongated reinforcing or tensioning member 4 in the form of a continuous helical assembly comprising a plurality of continuous wraps on the periphery of the pipe section 2. The reinforcing member 4 is placed on the pipe section preferably by a progressive wrapping or winding under tension. The wrapping at the beveled end of the pipe section 2 comprises a plurality of wraps 6 of non-uniform spacing on an end portion extending from wrap 6a and having a final wrap 6b parallel to the beveled end 3. The ends of the reinforcing member may be fixedly secured to the body or pipe section 2 by any of various known types of anchor means indicated by numeral 10 at the beveled end for holding the reinforcing member against circumferential movement on the body. Another portion of the wrapping comprises a plurality of wraps 5 of uniform spacing on a portion of the pipe section distant from the beveled end.

The beveled end portion of the body 2 on which the non-uniformly spaced wraps are disposed is herein referred to as the short side portion designated 7a and the long side portion designated 8a with the shortest lengthwise dimension of the body 2 having the nonuniformly spaced wraps designated x and the longest lengthwise dimension designated y in the drawings for explanation purposes. More specifically, the spacing or pitch designated a between the wraps along the shortest lengthwise dimension x of side portion 7a is approximately the same throughout this length x and the spacing or pitch designated b between wraps along the 1ongest lengthwise dimension y of side portion 8a is approximately the same throughout this length. Further, the spacing or pitch of the uniform wrapping will preferably be equal in length to the spacing b and is so designated in the drawings.

The tension in the reinforcing member for nonuniformly spaced wrap at the beveled surface of the beveled end portion shown in FIG. 2 may be varied for each progressive wrap in a manner illustrated schematically in FIG. 3. The concrete pipe section 2 is encompassed by a line 11 representing tension by radial distance on the reinforcing member for each wrap. The tension in the reinforcing member at any point on the pipe which is measured along a radial distance is a minimum at circumferential midpoint of the short side portion 70 as designated T-l and progresses to a maximum at the circumferential midpoint of long side portion 8a as designated T-2 and then returns to a minimum tension T-l at the circumferential midpoint of the short side portion 7a for each wrap. Stated another way, the end portion of the pipe section may be separated into a short half 7a and a long half 80 by a vertical plane designated P-P passing through its center. The tension. of each wrap of the reinforcing member is of lesser degree along the short half than along the long half as is illustrated by a radial distance comparison on each side of plane PP. The tension in the reinforcing member 4 is proportioned for each wrap in the progressively increasing and decreasing manner as is illustrated in FIG. 3 to provide a similar stress exerted on the endportion of the beveled pipe section 2.

The tension in the reinforcing member or force applied to the pay-off end is regulated in a manner shown in FIG. 3 to coincide with the change in spacing between adjoining wraps on the end portion of the pipe section having the non-uniformly spaced wrapping. As shown the spacing between adjoining wraps from the circumferential midpoint of the short side portion 7a to the circumferential midpoint of the long side portion 8a increases progressively and from the circumferential midpoint of long side portion 8a to the circumferential midpoint of the short side portion 7a decreases progressively. Similarly as the spacing increases between each wrap the tensioning member progressively applies forces to a greater adjoining area of pipe section and as the spacing decreases between each wrap the reinforcing member applies forces to a lesser area of the pipe section. Therefore, by controlling the tension in the reinforcing member in increments circumferential of the pipe in a manner as shown in FIG. 3 more nearly balanced compression or stresses may be established throughout an end portion of a reinforced beveled pipe section. I

The beveled end portion of the concrete pipe section 2 in FIG. 4 has a reinforcing member 12 which is wrapped or wound with spacing similar to FIG. 2 and in' addition is provided with a pair of opposing anchors or holding assemblies 13 and 14 disposed at the juncture of the long and short side portions or halves 7a and 8a or in a vertical plane QQ dividing the pipe section into long and short side portions 7a and 8a. These holding assemblies may be of various types arranged and secured on the outer surface of the pipe section so that each wrap fitted thereon will be held against circumferential movement. These holding assemblies 13 and 14 preferably extend throughout the lengthwise extent of the non-uniformly wrapped end portion of the body 2 as shown.

In this position the tension in the reinforcing member may be controlled as shown in FIG. 5 by a line 15 about the pipe section 2 representing tension by radial distance so that there is substantially uniform tension along the short half 7a and an increased and uniform tension along the long half 8a on the end portion of the pipe section having non-uniformly spaced wraps.

In FIGS. 6 and 7 a system in generally schematic diagram form is shown for further explanation of the above described product and for describing a method of making said product. As shown the beveled pipe section 2 is disposed in an upright position on a rotary table 21. The table is driven through a suitable mechanical coupling by a motor 22 preferably electric. An overhead guide or support 23 is provided for stabilizing the upper beveled end of the pipe section during its rotary movement on the table 21.

The reinforcing member or wire 24 extends from a wound drum 25 and an end thereof is initially secured on the concrete pipe section at a point distant from or oppositely of the beveled end which may be located at various points throughout its lengthwise extent as required. Rotation of the pipe section 2 in the counterclockwise direction as viewed in FIG. 6 will then serve to wrap the reinforcing member 24 on the pipe section. A spacer assembly 26 which moves vertically adjoining the pipe section will space the wraps as required. A braking device 27 is coupled to the drum 25 so as to brake the rotary motion of the drum thereby applying a selected degree of tension or pulling force to the payoff end of the reinforcing member 24 during its wrapping on the pipe section.

A pickup device 28-is mounted adjoining the table for sensing the angular position of the pipe section. A tension control stage 31 is responsive to the pickup device 28 through line 32 and adjusts the braking device through line 33. A drive control stage 34 is responsive to the change in the braking device and adjusts the speed of the drive motor 22 through lines 35 and 36, coupled between motor 22 and stage 34, line 37 coupled between stages 31 and 34 and line 38 coupled between brake 27 and stage 31.

As an example, the braking device 27 and drive motor 22 may be direct current motors. The brake stage 27 may have a winding which adjusts the torque on its output shaft coupled to the drum 25 in ac cordance with the voltage applied thereto. In this case the control stage 31 would change the voltage setting at line 33 on each half revolution so as to increase the torque and thus the tension in the reinforcing member 24. The drive motor 22 would also have a separate winding connected to lines 35 and 36 so that a change in torque in motor 27 would produce a change in voltage at lines 37 and 38 and thereby adjust the motor 22 to increase its torque and maintain the table rotary at a constant speed when the tension on member 24 increases.

In this manner the tensioning force exerted in the reinforcing member as it is being wrapped may be decreased or relieved on one half of the periphery of the pipe section and maintained or increased on the other half of the periphery as shown in FIGS. 3 and 5 while the table is rotated at a substantially constant speed.

While the present invention has been described with reference to particular structure, there is no intent to limit the spirit and scope to the precise details except as defined in the appended claims.

We claim: 1. A method of producing a reinforced concrete structure having at least one beveled end comprising the steps of wrapping an elongated reinforcing member around a hollow concrete body at the beveled end in a continuous helical pattern of multiple wraps throughout the lengthwise extent of the reinforcing inembenalternately applying a lesser degree of tension to the reinforcing member during said wrapping along the short side portion of the concrete body and a greater degree of tension to the reinforcing body during said wrapping along the long side portion of the concrete body and holding said helical assembly against circumferential movement on said body to provide a balanced stress in'the reinforced portion of said beveled concrete body.

2. The method of making a reinforced concrete structure which comprises the steps of:

securing one end of a reinforcing member at a selected point on a hollow concrete body;

wrapping said reinforcing member from the point at which it is attached around a selected outer portion of said concrete body in a helical pattern whereby to form a plurality of helical wraps of said reinforcing member around the selected portion of said concrete body;

varying the tension at which said reinforcing member is. wrapped in a predetermined manner so as to provide a substantially balanced stress in the selected portion of said concrete body; and securing the second end of said reinforcing member to said concrete body whereby to hold the reinforcing member against circumferential movement on said concrete body; said method further including the step of mounting a plurality of holding means at selected points on the selected outer portion of said concrete body, said reinforcing member being wrapped over and anchored at said selected points on said concrete structure to maintain differential tension on said reinforcing member.

3. The method of making a reinforced concrete structure which comprises the steps of:

securing one end of a reinforcing member at a selected point on a hollow concrete body;

wrapping said reinforcing member from the point at which it is attached around a selected outer portion of said concrete body in a helical pattern whereby to form a plurality of helical wraps of said reinforcing member around the selected portion of said concrete body;

varying the tension at which said reinforcing member is wrapped in a predetermined manner so as to provide a substantially balanced stress in the selected portion of said concrete body; and securing the second end of said reinforcing member to said concrete body whereby to hold the reinforcing member against circumferential movement of said concrete body,

the selected outer portion of said concrete body around which said reinforcing member is wrapped being a beveled tubular end portion,

said method further including the step of mounting a plurality of longitudinal extending holding means on the outer periphery of said beveled end portion prior to wrapping said reinforcing member on said concrete body, said holding members being each mounted on opposite sides of said beveled end portion midway between the long and short length of said beveled end portion whereby to divide said beveled end portion into long and short side portions, said reinforcing member being wrapped at a first tension along said long side portion and at a second tension lesser than said first tension along said short side portion, said reinforcing member being wrapped over and anchored in said holding means whereby differential tension is maintained on said reinforcing member.

4. The method recited in claim 3 wherein said reinforcing member is wire. 

1. A method of producing a reinforced concrete structure having at least one beveled end comprising the steps of wrapping an elongated reinforcing member around a hollow concrete body at the beveled end in a continuous helical pattern of multiple wraps throughout the lengthwise extent of the reinforcing member, alternately applying a lesser degree of tension to the reinforcing member during said wrapping along the short side portion of the concrete body and a greater degree of tension to the reinforcing body during said wrapping along the long side portion of the concrete body and holding said helical assembly against circumferential movement on said body to provide a balanced stress in the reinforced portion of said beveled concrete body.
 2. The method of making a reinforced concrete structure which comprises the steps of: securing one end of a reinforcing member at a selected point on a hollow concrete body; wrapping said reinforcing member from the point at which it is attached around a selected outer portion of said concrete body in a helical pattern whereby to form a plurality of helical wraps of said reinforcing member around the selected portion of said concrete body; varying the tension at which said reinforcing member is wrapped in a predetermined manner so as to provide a substantially balanced stress in the selected portion of said concrete body; and securing the second end of said reinforcing member to said concrete body whereby to hold the reinforcing member against circumferential movement on said concrete body; said method further including the step of mounting a plurality of holding means at selected points on the selected outer portion of said concrete body, said reinforcing member being wrapped over and anchored at said selected points on said concrete structure to maintain differential tension on said reinforcing member.
 3. The method of making a reinforced concrete structure which comprises the steps of: securing one end of a reinforcing member at a selected point on a hollow concrete body; wrapping said reinforcing member from the point at which it is attached around a selected outer portion of said concrete body in a helical pattern whereby to form a plurality of helical wraps of said reinforcing member around the selected portion of said concrete body; varying the tension at which said reinforcing member is wrapped in a predetermined manner so as to provide a substantially balanced stress in the selected portion of said concrete body; and securing the second end of said reinforcing member to said concrete body whereby to hold the reinforcing member against circumferential movement of said concrete body, the selected outer portion of said concrete body around which said reinforcing member is wrapped being a beveled tubular end portion, said method further including the step of mounting a plurality of longitudinal extending holding means on the outer periphery of said beveled end portion prior to wrapping said reinforcing member on said concrete body, said holding members being each mounted on opposite sides of said beveled end portion midway between the long and short length of said beveled end portion whereby to divide said beveled end portion into long and short side portions, said reinforcing member being wrapped at a first tension along said long side portion and at a second tension lesser than said first tension along said short side portion, said reinforcing member being wrapped over and anchored in said holding means whereby differential tension is maintained on said reinforcing member.
 4. The method recited in claim 3 wherein said reinforcing member is wire. 